1. Field of the Invention
This invention relates to automatic fertilizer systems and particularly to automatic fertilizer systems used with automatic sprinkler systems.
2. Description of the Prior Art
Underground sprinkler systems have been used for many years to water lawns. Typically, these systems use buried flexible PVC pipe to feed a number of sprinkler heads placed about a lawn. Alternatively, perforated pipe may be substituted for the sprinkler heads. In this case, the perforations disburse water into the ground directly watering a lawn.
One advantage of these systems is that fertilizer and other enhancements can be added directly to the water stream, thereby spreading these enhancements over the entire lawn during the watering process. One example of such a device is found in U.S. Pat. No. 6,230,987. This patent describes an applicator that allows a predetermined flow of a fluid for dissolving and distributing soluble substances that comprises a cap and a hollow cylindrical housing. The hollow cylindrical housing comprises of an enlarged chamber having a narrowed inlet port at its lower end. The narrowed inlet port has external threads connecting to a Tee pipe fitting of a pipeline of a fluid system and has a cylindrical flow channel extending to the enlarged chamber. The cylindrical flow channel has six equal V flow passages which are constructed by six vertical dividing walls locating at equal spaces around the wall of the cylindrical flow channel and extending inward to the axis of the cylindrical flow channel. The six equal V flow passages have six equal vertical openings, which are constructed by the vertical dividing walls and disposed outside the cylindrical flow channel of the narrowed inlet port at a predetermined length. The six equal vertical openings comprises of three vertical inlets and three vertical outlets. The six equal vertical openings have a same bottom wall, which is constructed, at the lower end of the vertical dividing walls. The same bottom wall has a diameter smaller than the minor diameter of the external threads of the narrowed inlet port. The system is designed so that when an user turns on his sprinkler system, the inventing applicator will precisely allow a predetermined portion of water in the horizontal flow channel of the Tee pipe fitting into the three vertical inlets 34 through their V flow passages 30 to the enlarged chamber 24 for mixing with and dissolving soluble substances at a predetermined flow ratio. A mixture, which is formed inside the enlarged chamber, flows through the other three V flow passages 30 of the three vertical outlets 34 and is diluted in a downstream flow of water in the horizontal flow channel of the Tee pipe fitting at a predetermined flow 3 ratio. For more effective distribution of the soluble substances to any large areas of lawns, gardens, golf courses, vegetable fields, agricultural fields etc., the user may install the inventing applicators at equal distances along their sprinkler pipelines. This invention helps the user save time, labor and cost for dissolving and distributing the soluble substances into their sprinkler systems. While useful in certain applications it requires several units to distribute the solutions to different zones of a lawn or garden (i.e., on of the units is needed for each zone.)
Another device for distributing such enhancements is found in U.S. patent application 2002/0145057. This application discloses a fertilizer-mixing device for sprinkler systems including a water inlet pipe having a water inlet, a first water outlet, and a second water outlet. The water inlet is in communication with an existing water source. A mixing chamber is adapted for holding a predetermined amount of fertilizer and water therein. The mixing chamber comprises a housing having a first opening therein for receiving the first water outlet of the water inlet pipe therein. The housing has a check valve disposed therein. The check valve includes an input pipe and an output pipe. A water outlet pipe is provided that has a first water inlet, a second water inlet, and a water outlet. The first water inlet is in communication with the second water outlet of the water inlet pipe. The second water inlet pipe is in communication with the output pipe of the check valve of the mixing chamber. The water outlet is connectable with an existing sprinkler system. Thus, this system allows water to enter the mixing chamber, where it mixes with the desired enhancements and then discharges back into the main flow line. Again, while this system works well of a single zone operation, there is no way to dispense fertilizer or other enhancements in balanced and measured amounts to different zones of operation.